Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and non-destructive, so the description's job is lighter. It still adds valuable behavioral context: results are indexed snapshots, every variant carries the seller, and price/stock must be verified via get_product. This is exactly the kind of non-obvious behavior an agent needs to know.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single dense paragraph front-loads the purpose, then covers the key parameter semantics and ends with the crucial verification caveat. There is no filler, and every sentence contributes to correct invocation.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a search tool with no output schema and a large nested input schema, the description covers the main invocation path and a key post-search behavior. It does not mention pagination or how to interpret the indexed snapshot structure beyond seller-on-variant, but the most important usage and verification context is present.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the burden. It explains catalog.query as free text, filters.categories as canonical taxonomy values, filters.price as ISO 4217 minor units, and the default currency. It does not explain other schema fields like pagination, signals, or attribution, but the most decision-critical parameter semantics are covered.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states this is a UCP Catalog search across independent WooCommerce merchants in KaliCart Global, which is a specific verb+resource. It also implicitly distinguishes from get_product by telling the agent to verify the chosen product there, making the search tool's role unmistakable.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives concrete guidance: use catalog.query for free text, use canonical category values from products[].categories, and use get_product before quoting price or stock. It does not explicitly contrast with lookup_catalog, so there is a minor usage-selection gap, but the practical context is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.